Two characters of mine have been ruined by the neverending magical sound effect glitch. My first had a sizzling sound that wouldn't go away no matter if I dropped everything he was carrying.
My second has a tingling sound that has actually begun to hurt my ears after listening to it for too long.

Has anyone else encountered this and can anyone help me?

Only in TOR but I don't cast spells in Skyrim.....what sound card/onboard sound are you using?

Read through this thread:

http://www.gamesas.com/topic/1335794-magic-crackling-sound-threatening-my-sanity/page__p__20116464__hl__sound__fromsearch__1#entry20116464

This outlines the issue I was having (sounds very similar to yours), and another user helped me out with a solution. If you sent me a PM with your email, I can send you a copy of the edited files he sent me that fixed the problem permanently. A quick temporary fix is to open the console and type sixchange, this eliminates the sound for awhile, if/when it comes back you just have to enter the command again.

when this first occured.. why didn't you emediately reload from a previous save?

I can answer that one, it's very subtle at first, enough so that you don't necesarily even notice that the sound is something that isn't supposed to be there.

You got it max - i use a flame atronach a lot and I thought that was her following behind me. You really don't notice it much, until its all you can hear. I read through your other post - did you basically just remove the sound of all frost magic from the game? What about when you or someone else casts the spell?

That's exactly what I ended up doing. To be perfectly honest I don't really know what happens soundwise when someone casts a frost spell, I don't use it personally and don't have followers. I think it still plays a sound in that case but don't know for sure.